Check if field exists in for function PHP

Question

I have this PHP script:

for ($desc=1; $_POST['ddata'.$desc]; $desc++) { 
    if($_POST['ddata'.$desc]){
        if ($desc == 1){
            $ddata = $_POST['ddata'.$desc];
            $dlocatie = $_POST['dlocatie'.$desc];
        } else {
            $ddata = $ddata.' / '.$_POST['ddata'.$desc];
            $dlocatie = $dlocatie.' / '.$_POST['dlocatie'.$desc];
        }
    }
}

If I have 5 ddata fields, it gives this error: Undefined index: ddata6

How can I check if that fields exists so I can prevent this error?

Is `$desc` 0 - 4 or 1 - 5? – DevlshOne Nov 27 '13 at 14:31 — DevlshOne, Nov 27 '13 at 14:31

score 2 · Accepted Answer · answered Nov 27 '13 at 14:28

2

How can I check if that fields exists so I can prevent this error?

use isset() to check if item exists prior accessing it.

answered Nov 27 '13 at 14:28

Marcin Orlowski

72,056
11
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score 2 · Answer 2 · answered Nov 27 '13 at 14:29

2

Instead of if($_POST['ddata'.$desc]), you can do:

if(isset($_POST['ddata'.$desc]))

Or:

if(array_key_exists('ddata'.$desc, $_POST))

answered Nov 27 '13 at 14:29

BenM

52,573
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168

score 0 · Answer 3 · answered Nov 27 '13 at 14:29

0

You can go for

if(isset($_POST['thekey']))

or more traditionally:

if(array_key_exists('thekey', $_POST))

answered Nov 27 '13 at 14:29

Pierre Arlaud

4,040
3
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score 0 · Answer 4 · answered Nov 27 '13 at 14:29

0

Try

 isset($_POST['ddata'.$desc])

Thanks

answered Nov 27 '13 at 14:29

user7789076

798
2
12
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score 0 · Answer 5 · answered Nov 27 '13 at 14:30

Check for what fields exist BEFORE you do your loop, by using preg_grep to scan the array for your ddata... fields.

$ddata_fields = preg_grep('/^ddata\d+$/', array_keys($_POST));
foreach($ddata_fields as $field) {
    $ddata = $_POST[$field];
    etc...
}

score 0 · Answer 6 · answered Nov 27 '13 at 14:30

0

Just add a if(isset($_POST['ddata'.$desc])){} instead of if($_POST['ddata'.$desc]){}

answered Nov 27 '13 at 14:30

Jan Heinrich Reimer

741
10
25

score 0 · Answer 7 · answered Nov 27 '13 at 14:44

Change the section beginning with...

if($_POST['ddata'.$desc]){

To....

for ($desc=1; $_POST['ddata'.$desc]; $desc++) { 
    if (isset($_POST['ddata'.$desc])) {
        $ddata = $_POST['ddata'.$desc'];
    } else {
        continue;
    }
    switch($desc) {
    case "1" :
        $ddata = $_POST['ddata'.$desc];
        $dlocatie = $_POST['dlocatie'.$desc];
    break;
    case "2" :
    case "3" :
    case "4" :
    case "5" :
        $ddata = $ddata.' / '.$_POST['ddata'.$desc];
        $dlocatie = $dlocatie.' / '.$_POST['dlocatie'.$desc];
    break;
    }
}

Check if field exists in for function PHP

7 Answers7